Here is Silas and his family in 1851:
HO107/1892/79 p18
Dean, Barnstaple Landkey Barnstaple, Devon
Richard BLACKMORE Head M 50 M Farmer 65 Ac Emp 1 Lab b Devon
Mary BLACKMORE Wife M 48 F b Arlington Devon
Anne BLACKMORE Daur U 17 F Farmers Dau b Bishops Tawton Devon
Charles BLACKMORE Son U 15 M Farmers Son b Bishops Tawton Devon
Silas BLACKMORE Son U 12 M b Bishops Tawton Devon
Samuel BLACKMORE Son U 10 M b Bishops Tawton Devon
Joshua BLACKMORE Son U 7 M b Bishops Tawton Devon
Richard BLACKMORE Son U 3 M b Bishops Tawton Devon
Mary ACKLAND Serv 15 F Gen Serv b Bratton Fleming Devon
That should help a wee bit.

Nell